> there is research being done into carbon nanotube rectennas. Theoretical efficiency is in the upper 90's I googled optical rectenna. "An optical rectenna—a

> there is research being done into carbon nanotube rectennas. Theoretical efficiency is in the upper 90's I googled optical rectenna. "An optical rectenna—a device that directly converts free-propagating electromagnetic waves at optical frequencies to direct current" [1] [1] https://www.nature.com/articles/nnano.2015.220 https://www.nature.com/articles/nnano.2015.220